安装好salt-master和salt-minion之后，发现无法启动服务。
使用systemctl status salt-master命令查看，提示报错：
ImportError: cannot import name EscapeFormatter
Linux系统版本是：
# cat /etc/redhat-release CentOS Linux release 7.5.1804 (Core)
salt-master的版本是：
# yum info salt-master Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile Installed Packages Name : salt-master Arch : noarch Version : 3000.9 Release : 1.el7 Size : 3.0 M Repo : installed From repo : salt-latest Summary : Management component for salt, a parallel remote execution system URL : http://saltstack.org/ License : ASL 2.0 Description : The Salt master is the central server to which all minions connect.
解决方法：
# pip install --upgrade pip # pip uninstall markupsafe # pip install markupsafe
检验结果：
# python Python 2.7.5 (default, Jul 13 2018, 13:06:57) [GCC 4.8.5 20150623 (Red Hat 4.8.5-28)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> from markupsafe import EscapeFormatter >>>
import没有报错，就说明已经OK了。
参考文档：https://stackoverflow.com/questions/51998470/while-starting-airflow-webserver-importerror-cannot-import-name-escapeformatt/51998488
